*: remove THREAD_ON macros, add nullity check

The way thread.c is written, a caller who wishes to be able to cancel a
thread or avoid scheduling it twice must keep a reference to the thread.
Typically this is done with a long lived pointer whose value is checked
for null in order to know if the thread is currently scheduled.  The
check-and-schedule idiom is so common that several wrapper macros in
thread.h existed solely to provide it.

This patch removes those macros and adds a new parameter to all
thread_add_* functions which is a pointer to the struct thread * to
store the result of a scheduling call. If the value passed is non-null,
the thread will only be scheduled if the value is null. This helps with
consistency.

A Coccinelle spatch has been used to transform code of the form:

  if (t == NULL)
    t = thread_add_* (...)

to the form

  thread_add_* (..., &t)

The THREAD_ON macros have also been transformed to the underlying
thread.c calls.

Signed-off-by: Quentin Young <qlyoung@cumulusnetworks.com>

1 files changed, 7 insertions, 9 deletions

diff --git a/lib/spf_backoff.c b/lib/spf_backoff.c
index e923f232b..9a9af8db2 100644
--- a/lib/spf_backoff.c
+++ b/lib/spf_backoff.c
@@ -169,21 +169,19 @@ long spf_backoff_schedule(struct spf_backoff *backoff)
     {
     case SPF_BACKOFF_QUIET:
       backoff->state = SPF_BACKOFF_SHORT_WAIT;
-      THREAD_TIMER_MSEC_ON(backoff->m, backoff->t_timetolearn,
-                           spf_backoff_timetolearn_elapsed, backoff,
-                           backoff->timetolearn);
-      THREAD_TIMER_MSEC_ON(backoff->m, backoff->t_holddown,
-                           spf_backoff_holddown_elapsed, backoff,
-                           backoff->holddown);
+      thread_add_timer_msec(backoff->m, spf_backoff_timetolearn_elapsed,
+                            backoff, backoff->timetolearn,
+                            &backoff->t_timetolearn);
+      thread_add_timer_msec(backoff->m, spf_backoff_holddown_elapsed, backoff,
+                            backoff->holddown, &backoff->t_holddown);
       backoff->first_event_time = now;
       rv = backoff->init_delay;
       break;
     case SPF_BACKOFF_SHORT_WAIT:
     case SPF_BACKOFF_LONG_WAIT:
       THREAD_TIMER_OFF(backoff->t_holddown);
-      THREAD_TIMER_MSEC_ON(backoff->m, backoff->t_holddown,
-                           spf_backoff_holddown_elapsed, backoff,
-                           backoff->holddown);
+      thread_add_timer_msec(backoff->m, spf_backoff_holddown_elapsed, backoff,
+                            backoff->holddown, &backoff->t_holddown);
       if (backoff->state == SPF_BACKOFF_SHORT_WAIT)
         rv = backoff->short_delay;
       else